栉孔扇贝(♀)×虾夷扇贝(♂)受精细胞学观察

Cytological Observations on Cross Fertilization between Chlamys farreri(♀) and Patinopecten yessoensis(♂) Scallops

采用Bouin氏液固定、石蜡包埋、切片 ,用苏木精 伊红染色 ,在光学显微镜下观察栉孔扇贝 (♀ )与虾夷扇贝 (♂ )杂交的受精细胞学过程。尽管栉孔扇贝与虾夷扇贝同科不同属 ,但它们的杂交仍具有正常的受精细胞学程序。栉孔扇贝卵子处于第一次成熟分裂中期时接受虾夷扇贝的精子入卵 ,精卵混合后 6min精子入卵 ;8～ 1 0min精核略微膨胀 ;2 5～ 3 0min排出第一极体 ;1h左右 ,雌雄原核同时形成 ;1小时 3 0分钟左右 ,雌雄原核融合 ;2h左右开始卵裂。杂交过程中的精子入卵行为较本交迟缓 。

Cytological observations on cross fertilization between Chlamys farreri (♀) and Patino\|pecten yessoensis (♂) were carried out. As observed, the process of cross fertilization between these two species was similar to intraspecific fertilization even though they belong to the different genera. The appropriate time of insemination was at the metaphase of the meiosis. By the sixth minute postinsemination, sperm was seen entering the egg cytoplasm. By the eighth to tenth minute postinsemination, the size of the sperm nucleus had increased slightly. By the 25-30th minute postinsemination, the first polar body was ejected. By the 60?th minute postinsemination, the male and female pronuclei were formed. By the 90?th minute postinsemination, the male and female pronuclei were fused to form the nucleus of the zygote. By the second hour postinsemination, zygote cleavage began. Embryogenesis in crossbreeding seemed to be slower than that in intraspecific fertilization.